Since the introduction of the digital computer, electronic storage devices have been a vital resource for the retention of data. Conventional semiconductor electronic storage devices typically incorporate capacitor and transistor structures, such as Dynamic Random Access Memory (DRAM), which temporarily store data based on the charged state of the capacitor structure. In general, this type of semiconductor Random Access Memory (RAM) often requires densely packed capacitor structures that are easily accessible for electrical interconnection. Many of these capacitor structures are fabricated with layers of material including semiconductor, dielectric, and metal. DRAM typically uses a cell structure based on a capacitor and a transistor.
Integrated circuit manufacturers increasingly face difficulties with scaling. The area of the chip (“real estate”) provided for capacitors in DRAM cells is rapidly shrinking. One way to attain smaller capacitor sizes and maintain storage capacity is to make the dielectric constant, or the K value, of the selected dielectric material very high. Metal oxides, especially transition metals, are commonly contemplated for high capacity DRAMs. One example, tantalum oxide (Ta2O5) has a K-value of approximately 25, and is a preferred dielectric material for DRAM cell capacitors for modern DRAM capacitors. Hafnium oxide (HfO2) is also used as a capacitor dielectric, but the K value is approximately 20. These K-values may not be sufficient as DRAM memory cell capacitors shrink. Barium strontium titanate (Ba0.5Sr0.5TiO3), or BST, has a dielectric constant of approximately 300, but BST is difficult to integrate into an integrated circuit. For these reasons, additional dielectric constant materials are needed for capacitors.